1. Field
Example embodiments of the following disclosure relate to an image processing apparatus and method, and more particularly, to an apparatus and method for rendering an image in a spherical harmonics (SH)-based lighting environment.
2. Description of the Related Art
Generally, a spherical harmonics (SH) basis refers to a small number of parameters per frequency band, capable of expressing intensity of all directions. Further, SH may refer to functions that are defined on a sphere. As such, the SH basis is widely applied in various fields including physics, for example. In the field of image processing, the SH basis is applicable even to rendering based on an environment map defined in all directions and may also be used for rendering of a diffuse surface.
Different from lighting or material which are globally defined, visibility information is defined for every surface point. Therefore, since data quantity of the visibility information is great, it is more efficient to read out a stored value through pre-computation in real time rather than computing the information in real time. Accordingly, this method is difficult to be directly applied to dynamic geometry incapable of pre-computation.
Conventionally, the SH based accesses have been already suggested. However, lighting environments have not been considered properly. Also, it is difficult to consider a difference in intensity of every direction with respect to a lighting environment map.